Change search
ReferencesLink to record
Permanent link

Direct link
KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Sweden .
KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Sweden .ORCID iD: 0000-0002-7304-021X
2014 (English)In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 795, no 1, L8- p.Article in journal (Refereed) Published
Abstract [en]

We show that in the presence of a magnetic field that is varying harmonically in space, the fundamental mode, or f-mode, in a stratified layer is altered in such a way that it fans out in the diagnostic k omega diagram, with mode power also within the fan. In our simulations, the surface is defined by a temperature and density jump in a piecewise isothermal layer. Unlike our previous work (Singh et al. 2014), where a uniform magnetic field was considered, here we employ a non-uniform magnetic field together with hydromagnetic turbulence at length scales much smaller than those of the magnetic field. The expansion of the f-mode is stronger for fields confined to the layer below the surface. In some of those cases, the k omega diagram also reveals a new class of low-frequency vertical stripes at multiples of twice the horizontal wavenumber of the background magnetic field. We argue that the study of the f-mode expansion might be a new and sensitive tool to determine subsurface magnetic fields with azimuthal or other horizontal periodicity.

Place, publisher, year, edition, pages
2014. Vol. 795, no 1, L8- p.
Keyword [en]
magnetohydrodynamics (MHD), Sun: helioseismology, turbulence, waves
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:kth:diva-158413DOI: 10.1088/2041-8205/795/1/L8ISI: 000345455500008ScopusID: 2-s2.0-84908141066OAI: diva2:776362

QC 20150107

Available from: 2015-01-07 Created: 2015-01-07 Last updated: 2015-01-07Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Singh, Nishant K.Brandenburg, Axel
By organisation
Nordic Institute for Theoretical Physics NORDITA
In the same journal
Astrophysical Journal Letters
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 22 hits
ReferencesLink to record
Permanent link

Direct link